X-Git-Url: https://git.immae.eu/?a=blobdiff_plain;f=preinstall.js;h=d53bca25827bca92282f3b542604d15237edfe04;hb=715fe0113813acb9e0cca251719c6394d4c3ab94;hp=071f1590eb2c9e922dc61abf5fd0083878e88855;hpb=03aaa7d3bbf9ff2176fe3b69138f37f5f265d186;p=github%2Ffretlink%2Fnode-dhall-json-bin.git

diff --git a/preinstall.js b/preinstall.js
index 071f159..d53bca2 100644
--- a/preinstall.js
+++ b/preinstall.js
@@ -4,6 +4,7 @@ const fs = require("fs");
 const path = require("path");
 
 const { https } = require("follow-redirects");
+const semver = require("semver");
 const tar = require("tar");
 const unbz2 = require("unbzip2-stream");
 const unzipper = require("unzipper");
@@ -11,13 +12,63 @@ const unzipper = require("unzipper");
 const pkg = require("./package.json");
 const bindir = path.join(__dirname, "bin");
 
-const trim = str => str && String(str).trim();
+const formatVersionKey = name =>
+  `${name}-version`;
+const toSnakeCase = name =>
+  name.replace(/-/g, '_');
+const formatNpmCfgVar = name =>
+  toSnakeCase(name.toLowerCase());
+const formatEnvVar = name =>
+  toSnakeCase(name.toUpperCase());
+const prefixNpmCfgKey = key =>
+  `${pkg.name}:${key}`;
 
-const dhallVersion = trim(pkg["dhall-version"] || process.env.DHALL_VERSION);
-if (!dhallVersion) throw new Error("Missing DHALL_VERSION environment variable.");
+const readVersionWith = (lookup, discard = () => {}) => name => {
+  const key = formatVersionKey(name);
+  const version = lookup(key);
+  return version ? {
+    get version() { return String(version).trim() },
+    discard() { discard(key, version) },
+    orElse(alt) { alt.discard(); return this }
+  } : {
+    get version() {
+      throw new Error(`Missing \`${name}\` version! You can provide it as a \`${prefixNpmCfgKey(key)}\` npm configuration parameter or as a \`${formatEnvVar(key)}\` environment variable.`);
+    },
+    discard() {},
+    orElse(alt) { return alt }
+  };
+};
+
+const readPkgVersion = readVersionWith(key => pkg[key]);
+const readCfgVersion = readVersionWith(key => {
+  return process.env[`npm_config_${formatNpmCfgVar(pkg.name)}_${formatNpmCfgVar(key)}`];
+}, (key, version) => {
+  console.warn(`Ignoring \`${prefixNpmCfgKey(key)}\` npm configuration parameter (${version}).`);
+});
+const readEnvVersion = readVersionWith(key => {
+  return process.env[formatEnvVar(key)];
+}, (key, version) => {
+  console.warn(`Ignoring \`${formatEnvVar(key)}\` environment variable (${version}).`);
+});
+
+const readVersion = name =>
+  readPkgVersion(name)
+    .orElse(readEnvVersion(name))
+    .orElse(readCfgVersion(name))
+    .version;
+
+const dhallVersion = readVersion("dhall");
+const dhallJsonVersion = readVersion("dhall-json");
 
-const dhallJsonVersion = trim(pkg["dhall-json-version"] || process.env.DHALL_JSON_VERSION);
-if (!dhallJsonVersion) throw new Error("Missing DHALL_JSON_VERSION environment variable.");
+const isLowerThan = (version, upperBound) =>
+  semver.valid(version) && semver.lt(version, upperBound);
+
+if (isLowerThan(dhallJsonVersion, "1.2.8")) {
+  throw new Error(`This release of the \`${pkg.name}\` npm package installs \`json-to-dhall\`, which isn’t provided by \`dhall-json@<1.2.8\`.`);
+}
+if (isLowerThan(dhallJsonVersion, "1.3.0")) {
+  throw new Error(`This release of the \`${pkg.name}\` npm package installs \`yaml-to-dhall\`, which isn’t provided by \`dhall-json@<1.3.0\`.`);
+}
 
 const release = `https://github.com/dhall-lang/dhall-haskell/releases/download/${dhallVersion}/dhall-json-${dhallJsonVersion}`;